ATS Pulmonary Function Laboratory Manual

ATS Pulmonary Function Laboratory Management & Procedure Manual | 3rd Edition

1.3.

Exercise variables 1.3.1.

Total distance walked reported in meters or feet

1.3.2.

Oxygen usage, if applicable 1.3.2.1.

Liter flow (continuous or pulsed)

1.3.2.2. 1.3.2.3.

Delivery device (nasal cannula, oxygen pendent) Mode of transport (carried shoulder unit or pushed/pulled tank)

1.3.3. 1.3.4. 1.3.5. 1.3.6.

Dyspnea using Borg scale scores, or Visual Analog Scale scores

Reason for early termination, if applicable Heart rate response including recovery

Oxygen saturation (Sp O 2 )

Procedure Notes 1. Sources of Variability There are many sources of variability in this test, including height, age, weight, disease, and musculo-skeletal disor- ders. Procedural sources of variability will be controlled as much as possible. 2. Learning Effect There is strong evidence of a learning effect for the 6MWD when two or more tests are conducted. Most reports indicate that the second 6MWD is somewhat higher than the first (16–19). One large study reported a 95% con- fidence interval for the learning effect of 24–29 meters (20). The learning effect appears to be moderated by test repetition and practice, at least in the short term. Three studies reported that there was a statistically significant increase in 6MWD between walks 1 and 3 on a single day; however, one of these studies reported no significant dif- ference in 6MWD for walks 2 and 3 (17, 21, 22). After three walks, further repetition did not consistently improve 6MWD (17, 22). A practice test is not needed in most clinical settings, but can be considered by the medical direc- tor of the laboratory. 3. Technologist Training and Experience Technologists who perform 6MWTs will be trained using this standard protocol, and then supervised by the labora- tory lead or medical director for several tests before performing them alone. 4. Instructions and Encouragement The script provided in this document will be used to explain the test and instruct the patient. Standardized phrases of encouragement will be used each minute during the test.

5. Supplemental O 2 If supplemental O 2

is needed during the walks, and serial tests are planned, then during all walks by that patient, O 2 will be delivered in the same way with the same flow. If the flow must be increased during subsequent visits due to worsening gas exchange, this should be noted on the worksheet, and considered during interpretation of the change noted in the 6MWD. The type of O 2 delivery device will also be noted on the report (e.g., patient carried liquid oxygen container).

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